Toggling the LANPHYPC Value bit cycles the power on the PHY and sets it
back to power-on defaults.  This includes setting it's MAC-PHY messaging
mode to use the PCIe-like interconnect, so the MAC must also be set back
from SMBus mode to PCIe mode otherwise the PHY can be inaccessible.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>